Transbronchial Cryobiopsy vs Conventional Forceps Biopsy in Lung Transplant Recipients Multicenter Study

Abstract

<h3>Purpose</h3> Transbronchial biopsy is considered the gold standard in the diagnosis of acute cellular rejection after lung transplantation. There still remains the discussion in conventional forceps biopsy comparing to cryobiopsy in lung transplant recipients. This study aims to compare the diagnostic yield and potential complications in both procedures. <h3>Methods</h3> In retrospective multicenter study all transbronchial biopsies (TBBs) were evaluated since 2010 till 2019. Surveillance TBBs were performed in 1, 3, 6 and 12 months after lung transplantation. Additional diagnostic bronchoscopies were performed if clinically indicated. Pneumothorax was categorized as none, partial recovered without treatment and pneumothorax required inserting of chest drainage. Bleeding was predefined as none, mild bleeding requiring suction and instillation of cold saline solution and severe bleeding requiring additional instillation of adrenaline. TBBs were graded according to the International Society of Heart and Lung Transplantation (ISHLT) consensus guidelines for the diagnosis of lung allograft rejection. <h3>Results</h3> In 309 patients a total of 448 forceps biopsies and 573 cryobiopsies were performed. The incidence of pneumothorax was significantly (p<0,001) higher after forceps biopsies (9,2 % vs 3,3 %). Bleeding was significantly greater in the cryobiopsy group (cryobiopsy/forceps biopsy: no bleeding 80,4%/96,4%; mild 15,4%/2,4%; severe 4,2%/1.1%; p < 0.001). The mean size of cryo-specimen was five times larger than forceps-group samples. The diagnostic rate of acute rejection using cryobiopsy and forceps biopsy was similar A0 grade 36% vs 39%, A1 grade 46% vs 35%, A2 grade 14% vs 17,5%, A3-A4 grade 4% vs 8,5%. But evidently larger specimens from cryobiopsy catched the presence of bronchiolus in 51% compared with 8% from forceps samples which shows the major significance (p<0,001). <h3>Conclusion</h3> Transbronchial cryobiopsies compared to traditional forceps biopsies provided superior quality of the specimens with significantly higher capture of bronchiolus and lower rate of non-diagnostic samples which also enable potential possibility for futher evaluation of humoral and chronic rejection. Cryobiopsies reduce the number of specimens with acceptable complications.